A double-sphere detection device and method for orbital atmospheric density

Abstract

The present invention provides a double-sphere detection device and method for orbital atmospheric density. The device includes a first spherical device and a second spherical device. The diameter of the first spherical device is larger than that of the second spherical device, and the two spherical devices are connected by a connecting force-measuring device. The orbital atmospheric damping force is usually of a small magnitude, which requires extremely high requirements for detection equipment and is difficult to research, develop and manufacture. The double-sphere detection method and device for orbital atmospheric density of the present invention utilize double spheres with a huge difference in area-mass ratio, which can cleverly convert non-contact atmospheric damping into tensile force, reduce the design requirements for measurement equipment, and effectively extend the detection life and improve the detection accuracy by adjusting the masses and windward areas of the two spheres.

Description

Technical Field

[0001] The present invention relates to the technical field of aerospace remote sensing, and more specifically, to a device and method for detecting orbital atmospheric density. Background Art

[0002] The Earth's thermospheric atmosphere is driven by solar activity. In the altitude range of 100 km to 1000 km, the sun is the main factor determining atmospheric changes. When solar activity is intense, the temperature and density of the thermospheric atmosphere also change drastically. There are significant differences in the thermospheric atmosphere between high and low solar activity years. The higher the altitude, the greater the influence of solar activity, but the atmospheric mass density decreases exponentially. The drastic changes in atmospheric density caused by solar activity directly affect the orbits of spacecraft, and thus affect the satellite orbit lifetime. Studying the problem of solar activity-induced satellite orbit perturbations is of great significance for formulating flight plans, satellite design and launch, collision warning, etc. In the scientific research on the propagation mechanism of the thermospheric atmosphere, detection information with smaller scales and higher time resolutions is required.

[0003] In the prior art, the methods for measuring orbital atmospheric density mainly include GPS orbit inversion and accelerometer inversion. Inverting the thermospheric atmosphere based on GPS orbits has advantages such as simple payload, low cost, and mature technology, but it cannot obtain density changes with small-scale spatial resolution, and the inversion scale is about in the order of hundreds of kilometers. Inverting the thermospheric atmospheric density with an accelerometer can achieve relatively high spatial resolution, but above an altitude of 500 km, the magnitude of the atmospheric damping acceleration is less than 10 -7 m / s 2 , which poses high technical requirements for accelerometer design and there are certain technical bottlenecks. Summary of the Invention

[0004] The purpose of the present invention is to overcome the problems of high design and manufacturing requirements or low measurement accuracy of existing orbital atmospheric density detection devices.

[0005] To achieve the above purpose, the present invention provides a double-sphere detection device for orbital atmospheric density, including a first spherical device A1 and a second spherical device A2. The diameter of the first spherical device A1 is larger than that of the second spherical device A2, and the two spherical devices are connected by a connecting force-measuring device B.

[0006] As an improvement of the above technical solution, the connecting force-measuring device B is composed of a rigid material and has no elasticity longitudinally.

[0007] As an improvement of the above technical solution, the connecting force-measuring device B is connected to the first spherical device and the second spherical device in a soft connection manner.

[0008] As an improvement of the above technical solution, the diameter of the first spherical device A1 is preferably 60 cm, and the mass is 1 kg to 5 kg.

[0009] As an improvement of the above technical solution, the diameter range of the second spherical device A2 is 20 cm to 30 cm, and the mass is 10 kg to 15 kg.

[0010] As an improvement of the above technical solution, the first spherical device A1 is composed of a spherical shell and an expansion unit.

[0011] As an improvement of the above technical solution, the spherical shell is composed of a load-bearing layer, an airtight layer, and a protective layer from the inside out.

[0012] The present invention also provides a method for measuring atmospheric density using a double-sphere detection device for orbital atmospheric density, including:

[0013] Moving horizontally in the direction of the second spherical device A2 with the second spherical device A2 in front and the first spherical device A1 behind;

[0014] Calculating the atmospheric density according to the areas, masses, moving speeds of the two spherical devices and the tension measured by the connected force measuring device B.

[0015] Among them, the calculation formula for atmospheric density is:

[0016]

[0017] Among them, f rope is the tension measured by the connected force measuring device (B), M1 is the mass of the first spherical device A1, A1 is the windward cross-sectional area of the first spherical device A1, M2 is the mass of the second spherical device A2, A2 is the windward cross-sectional area of the second spherical device A2, v r is the moving speed of the device, and C d is the drag coefficient.

[0018] The C d has a value range between 1.0 and 4.0 and varies according to factors such as altitude.

[0019] The double-sphere detection method and device for orbital atmospheric density provided by the present invention have the following advantages:

[0020] 1. Simple in design and manufacture, with low requirements for manufacturing processes, reducing the design and manufacturing threshold.

[0021] 2. Improve the detection accuracy of orbital atmospheric density.

[0022] 3. The device has a long on-orbit operation time and a long detection life.

[0023] 4. By taking advantage of the huge difference in the area-mass ratio of the designed double spheres, the non-conservative force of atmospheric damping is innovatively converted into tensile force, reducing the design requirements for measuring equipment. By adjusting the masses and windward areas of the two spheres, the detection life can be effectively extended and the detection accuracy can be improved. Description of the Drawings

[0024] Figure 1 The structure diagram of the double-sphere detection device for orbital atmospheric density is shown;

[0025] Figure 2 The tensile force analysis diagram of the double-sphere detection for orbital atmospheric density is shown. Detailed Embodiment

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0027] As Figure 1 shown, the double-sphere detection device for orbital atmospheric density is composed of a spherical device A1 and a spherical device A2. The spherical device A1 and the spherical device A2 are connected by a connecting force-measuring device B.

[0028] The spherical device A2 is composed of a power subsystem, a GNSS positioning device, a data transmission subsystem, etc. (The design and manufacture of the spherical device A2 itself involve a general platform for microsatellites, which is not the focus of the present invention and will not be elaborated here). The diameter of the spherical device A2 is generally between 20 cm and 30 cm, and the mass is generally between 10 kg and 15 kg.

[0029] The diameter of the spherical device A1 is larger than that of the spherical device A2, and it has the characteristics of light mass and large windward area relative to the spherical device A2. The diameter of the spherical device A1 is preferably 60 cm, and the mass is generally between 1 kg and 5 kg.

[0030] The spherical device A1 is composed of a spherical shell and an expansion unit. Specifically: the spherical shell consists of a load-bearing layer, an airtight layer, and a protective layer from the inside out. The material of the load-bearing layer can be high-strength polyethylene fiber, para-aramid, polyarylate fiber, Kynol, or PBO. The material of the airtight layer can be polyvinyl fluoride, polyvinylidene fluoride, polyvinylidene chloride, ethylene-vinyl alcohol copolymer, or polyester. The protective layer includes high molecular fluoride. The expansion unit is mainly composed of inert compressed gas.

[0031] The connecting force-measuring device B is made of rigid material and has no elasticity longitudinally. The connecting force-measuring device B is connected to the spherical device A1 and the spherical device A2 by a flexible connection method.

[0032] A force measuring device is provided on the connecting force measuring device B, which can measure the tensile force between two spherical center devices.

[0033] During use, the spherical device A2 is in the front and the spherical device A1 is in the back, and it moves horizontally in the direction of the spherical device A2. Under the action of the tensile force and air resistance, the spherical device A2, the connecting force measuring device B, and the spherical device A1 are arranged in sequence. The extension lines at both ends of the connecting force measuring device B respectively pass through the centers of the spherical device A1 and the spherical device A2. When the device moves, due to the larger windward area of the spherical device A1 relative to the spherical device A2, the corresponding air resistance is large, and a tensile force is generated on the connecting force measuring device B. The connecting force measuring device B can accurately measure the generated tensile force. When detecting the atmospheric density at different orbital heights, the movement speed of the device is different, about 7.9 km / s.

[0034] The present invention also provides a method for calculating the orbital atmospheric density by using the above device, as Figure 2 shown:

[0035] The formula for the air resistance received by the spherical device A1 is as follows:

[0036]

[0037] Among them, C d is the drag coefficient, and its value range is between 1.0 and 4.0, which varies according to factors such as height, and generally takes a value of 2.2; ρ is the atmospheric density at the position where the sphere is located, v r is the operating speed of the device (the movement speeds of the two spherical devices are the same), and A1 is the windward cross-sectional area of the spherical device A1 during movement.

[0038] The formula for the air resistance received by the spherical device A2 is as follows:

[0039]

[0040] Among them, A2 is the windward cross-sectional area of the spherical device A2 during movement.

[0041] Then the resultant force received by the device:

[0042] The resistance acceleration of the device movement is:

[0043]

[0044] Among them, M1 is the mass of the spherical device A1, and M2 is the mass of the spherical device A2.

[0045] The resultant force received by the spherical device A1:

[0046]

[0047] Among them, f rope is the tensile force on the connecting force measuring device B.

[0048] The tensile force on the connecting force measuring device B can be expressed as:

[0049]

[0050] Finally, the tensile force f measured by the rope rope , and the formula for inverting the atmospheric density ρ is:

[0051]

[0052] In the experiment, according to the maximum and minimum values of the atmospheric density at the altitudes of @300km, @400km, and @500km, the atmospheric damping tensile force under different area-mass ratios was calculated as shown in the following table:

[0053]

[0054]

[0055] It can be seen from the experimental data in the table that at an altitude of 500km, the minimum order of magnitude of the tensile force is 10 -6 N, and there is no bottleneck in technical implementation.

[0056] The double-sphere detection device for orbital atmospheric density proposed by the present invention uses two spheres with different area-mass ratios to ingeniously convert non-contact atmospheric damping into tensile force, reducing the design requirements for measuring equipment, and extending the detection life by adjusting the masses of the two spheres.

[0057] The present invention proposes a double-sphere detection device and method for orbital atmospheric density. By using the huge difference in the area-mass ratio of the designed double spheres, it innovatively converts the non-conservative force atmospheric damping into tensile force, reduces the design requirements for measuring equipment, and can effectively extend the detection life and improve the detection accuracy by adjusting the masses and windward areas of the two spheres.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not restrictive. Although the present invention has been described in detail with reference to the embodiments, those of ordinary skill in the art should understand that any modification or equivalent replacement of the technical solutions of the present invention does not depart from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A double - sphere detection method for orbital atmospheric density, implemented based on a double - sphere detection device for orbital atmospheric density. The device includes a first spherical device (A1) and a second spherical device (A2). The diameter of the first spherical device (A1) is larger than that of the second spherical device (A2), and the two spherical devices are connected by a connecting force - measuring device (B). The method includes: Moving horizontally in the direction of the second spherical device (A2) with the second spherical device (A2) in front and the first spherical device (A1) behind. Calculating the atmospheric density based on the areas, masses, moving speeds of the two spherical devices and the tension measured by the connecting force - measuring device (B). The calculation formula for atmospheric density is: Among them, f rope is the tensile force measured by the connecting force measuring device (B), M1 is the mass of the first spherical device (A1), A1 is the windward cross-sectional area of the first spherical device (A1), M2 is the mass of the second spherical device (A2), A2 is the windward cross-sectional area of the second spherical device (A2), v r is the moving speed of the device, and C d is the drag coefficient.

2. The double - sphere detection method for orbital atmospheric density according to claim 1, wherein: The connecting force - measuring device (B) is composed of a longitudinal rigid material and has no elasticity longitudinally.

3. The double - sphere detection method for orbital atmospheric density according to claim 2, wherein: The connecting force - measuring device (B) is connected to the first spherical device and the second spherical device in a soft - connection manner.

4. The double - sphere detection method for orbital atmospheric density according to claim 1, wherein: The diameter of the first spherical device (A1) is 60 cm, and its mass ranges from 1 kg to 5 kg.

5. The double - sphere detection method for orbital atmospheric density according to claim 1, wherein: The diameter range of the second spherical device (A2) is from 20 cm to 30 cm, and its mass ranges from 10 kg to 15 kg.

6. The double - sphere detection method for orbital atmospheric density according to claim 1, wherein: The first spherical device (A1) includes: a spherical shell and an expansion unit.

7. The double - sphere detection method for orbital atmospheric density according to claim 6, wherein: The spherical shell includes, from the inside out: a load - bearing layer, an air - tight layer, and a protective layer.

8. The double - sphere detection method for orbital atmospheric density according to claim 1, wherein: The value of Cd ranges from 1.0 to 4.0 and varies according to height factors.

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